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Influence of Potassium on the Synthesis of Methanethiol from Carbonyl Sulfide on Sulfided Mo/Al 2 O 3 Catalyst
Author(s) -
Gutiérrez Oliver Y.,
Kaufmann Christoph,
Lercher Johannes A.
Publication year - 2011
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201100124
Subject(s) - methanethiol , disproportionation , chemistry , catalysis , potassium , inorganic chemistry , physisorption , sulfidation , sulfide , sulfur , organic chemistry
Potassium‐doped MoS 2 catalysts supported on Al 2 O 3 were synthesized, characterized by using atomic absorption spectroscopy, N 2 physisorption, NO adsorption, X‐ray diffraction, temperature‐programmed sulfidation, and Raman spectroscopy, and tested in the synthesis of methanethiol from carbonyl sulfide (COS) and H 2 . The results revealed that two phases, pure MoS 2 and potassium‐decorated MoS 2 (formed at high potassium loadings), were present in the active catalysts. The main effect of potassium during sulfidation and during the catalytic reaction was to increase the mobility of surface oxygen or sulfur atoms. Thus, potassium promoted the disproportionation of COS to CO 2 and CS 2 and the production of CO from CO 2 . Additionally, potassium cations hindered the reductive decomposition of COS to CO and H 2 S and the hydrogenolysis of methanethiol to methane. Mars–van Krevelen‐type mechanisms were proposed to explain the disproportionation of COS on alumina and on the MoS 2 phases. The catalytic site in the potassium‐decorated MoS 2 phase was proposed to include a potassium cation as adsorption site.